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Many still don't know how to drive in winter

We've been spared much of the white stuff so far, but a brief preview of bad weather in December caught far too many by surprise.
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Winter has been kind to us so far here in the G.T.A. It appeared to take December off, but is now due to hit us with a vengeance.

Our first teaser of winter driving just before the end of the year proved many motorists forgot how to drive in slippery conditions. TV news reports showed many of them finding the ditch or bouncing off guard rails.

Living in the shadow of the Great Lakes means our weather can change drastically in a short time, or from one highway to the next. Snow squalls or hilly terrain can mean going from sunny dry roads to white-out conditions in less than 100 metres. Temperatures can drop a dozen degrees in a matter of hours. Roads can go from wet and slushy to ice before you can get home to your recliner.

More: Driving in a ‘Snowpocalypse’ – without winter tires

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In other words, being properly prepared for winter driving can be the difference between waiting hours in a ditch or at a collision reporting centre, and getting to your destination safely.

As driving conditions deteriorate, the level of adhesion between tire and road surface drops off dramatically, yet many drivers and truckers simply will not slow down.

Motorists should rate or grade the road they are driving on and adjust their speed and following distance accordingly.

Cold, dry roads with a coating of salt and/or sand do not offer as much grip as the same dry road does in summer conditions. Motorists should factor in the adhesion level of the road surface when they decide on a driving speed or following distance. They should also take into consideration whether they have winter tires fitted or all-season tires. Winter tires do provide a higher level of grip in all winter conditions than do all seasons.

Ice- and snow-covered roads might offer motorists just 10 per cent of the adhesion a dry road would provide. This means braking distances will be around 10 times longer than on a dry road. Driving speeds on multi-lane highways in these conditions should drop from 100 km/h in the summer to 20-to-50 km/h in these icy conditions for all vehicles, even those with all-wheel drive and for transport trucks too.

Snow- and slush-covered roads may give the driver perhaps 30 per cent of the grip available in summer. This means speed should drop from the clear road speeds to about 30-to-60 km/h. Braking distances can increase six to eight times longer than on dry roads.

Snowy wet roads may provide half the traction drivers experience on dry summer roads. Braking distances will range from three to seven times longer and speeds should be as low as 30-to-80 km/h, depending on whether it is more snowy or mostly just wet.

Salty, wet roads might offer motorists a grip level that is up to 80 per cent of what is available in summer. Braking distances can be in the order of two to four times longer and speeds should only be around the speed limit but not higher.

Dry, salt-covered roads will have, at most, 90 per cent of the grip of a dry summer road. If sand has been added to the mix that level of grip could drop to only 70 per cent. Braking distances could double on these roads.

Winter tires will definitely offer more grip in all these scenarios compared to all-season tires. However, they will not recoup the lost grip due to the road surface deterioration.

All-wheel drive technology will help you overcome the lack of grip only for acceleration and will not increase a tire’s grip for steering or stopping. Any motorist with all-wheel or four-wheel drive should slow down just like everyone else.

Slowing down in winter is paramount to safe driving. Any fool can drive fast. Smart drivers know when not to!

ianlaw@carcontrolschool.com

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